Document is locked when sent to external company

I set up a document for digital signatures, there are usually 2 signatures within my organisation and then 2 signatures required externally as well. No matter what I do as soon as the document leaves our organisation it is 'locked' for signature by the external company.  I have set up the emails so that if a different person is to sign it can be delegated to them. The lock option is not ticked prior to sending externally. 

Hoping someone can help?

Thanks

Phoebe